Prince Harry's girlfriend Meghan Markle has been subjected to a "wave of abuse and harassment" by the media, Kensington Palace has said.
In a strongly-worded statement, the Prince's Communications Secretary Jason Knauf revealed the difficulties the US actress has experienced since news of their relationship broke.
He said: "Since he was young, Prince Harry has been very aware of the warmth that has been extended to him by members of the public.
"He feels lucky to have so many people supporting him and knows what a fortunate and privileged life he leads.
"He is also aware that there is significant curiosity about his private life. He has never been comfortable with this, but he has tried to develop a thick skin about the level of media interest that comes with it.
"But the past week has seen a line crossed. His girlfriend, Meghan Markle, has been subject to a wave of abuse and harassment. Some of this has been very public - the smear on the front page of a national newspaper; the racial undertones of comment pieces; and the outright sexism and racism of social media trolls and web article comments.
"Some of it has been hidden from the public - the nightly legal battles to keep defamatory stories out of papers; her mother having to struggle past photographers in order to get to her front door; the attempts of reporters and photographers to gain illegal entry to her home and the calls to police that followed; the substantial bribes offered by papers to her ex-boyfriend; the bombardment of nearly every friend, co-worker, and loved one in her life.
"Prince Harry is worried about Ms Markle's safety and is deeply disappointed that he has not been able to protect her. It is not right that a few months into a relationship with him that Ms Markle should be subjected to such a storm."
The statement - which is is the first official confirmation from that the pair are dating - is an unusual move by the palace.
It added that it hopes the statement will cause the media to "reflect before any further damage is done".
Ms Markle, 35, is best known for her role in the TV drama Suits. She was married to film producer Trevor Engelson, but the couple split in 2013.
The couple are reported to have met in May when Harry was in Canada promoting the Invictus Games 2017.
Ms Markle, who lives in Toronto, has not commented on their relationship, but did share a picture of two embracing bananas on her Instagram account and described herself as the "luckiest girl in the world" in an interview.
Prince Harry has been single since he split from his long-term girlfriend Cressida Bonas more than two years ago.